Penguinboy, they aren't used much any more, but 5400RPM is/was an extremely common hard drive speed. Don't know what to say.
Anyway, some people are really good space savers, or just not space hogs. Not everybody needs or wants their entire game collection installed at one time, And not everybody torrents stuff as much as I or others do. 160GB is pretty damn small though, especially with game installs now commanding something like 20GB if I'm not mistaken. Something like 320GB would be much more realistic even if you're not undertaking huge downloads.
Oh, and I just checked Newegg. They sell a 320GB for 50 dollars, 8 bucks more and twice the size of that wimpy 160GB you got there. But hey, if you want to throw away your money on overpriced obsolete components, be my guest.